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1、细菌生物膜内容适合医学院3-5年级学生使用“In a paper in Science in 1999, we said 65 percent of all diseases in the developed world are biofilms,” Costerton said. “Now the NIH says 80 percent. ”Biofilms matrix-enclosed microbial accretions/逐渐生长/增加 that adhere to biological or non-biological surfaces.on a contact lenson
2、a spider细菌生物膜广泛存在于自然环境中细菌生物膜广泛存在于自然环境中 Biofilm formation appears early in the fossil record (3.25 billion years ago) and is common throughout a diverse range of organisms in both the Archaea/ 单细胞生物 and Bacteria lineages. Biofilm formation represents a protected mode of growth that allows cells to su
3、rvive in hostile environments and also disperse to colonize new niches.回肠表面的细菌生物被膜人体植入导管表面的细菌生物被膜细菌生物膜广泛存在于自然环境中真菌生物膜Biofilms can be harmful Catheters and prostheses (may lead to systemic infection) Dental disease （牙菌斑、口腔味道？） Otitis media/中耳炎, inflammatory bowel disease/IBD, prostatitis/前列腺炎, sinusi
4、tis/鼻窦 炎, etc.生物膜与疾病（总结）细菌生物膜 进入体内的 可能途径细菌生物膜的基本性质生物膜1978年由J. William Costerton等通过电过电 镜镜方法首次观观察到Biofilm定义义：指细细菌自身产产生的外部多糖基质质 、纤维纤维 蛋白质质、脂蛋白等包裹着的菌细细胞的结结构 。 生物被膜是细细菌的一种具有保护护性的生长长模式，是细细胞间间 相互协调协调 作用的复杂杂的多细细胞群体，具有结结构和代谢谢复杂杂 性。 形成生物被膜的黏附细细菌群也可以释释放出浮游细细菌，是潜 在的持续续感染因素。Biofilms matrix-enclosed microbial acc
5、retions/逐渐生长/增加 that adhere to biological or non-biological surfaces.古老：fossil record (3.25 billion years ago) Common：a diverse range of organisms Archaea/ 单细胞生物, bacteria，fungi Represents a protected mode of growth that allows cells to survive in hostile environments Can disperse to colonize new ni
6、ches/ 可以释释放出浮游细细菌，生长长迅速，是潜在感染因素Biofilm 特点总结Biofilm 的形成过程- 体内过程Biofilm 的形成过程- 从菌落角度细菌的初始吸附与 其鞭毛、菌毛有关Nature Rev Micro 2010像“铠甲”一样生物膜的结构特点化学组成 水分（97%） 胞外大分子 吸附的营营养物质质及代谢产谢产 物、细细菌裂解物 蛋白质质、DNA 细菌生物膜的结构特点生物膜的结构特点成熟生物被膜模型 由外到内依次为：生物被膜层（bulk of biofilm）连接层（linking film）条件层（conditioning film）基质层（substratum)
7、细菌被大量的胞外多糖包绕形成微菌落，各微菌落之间充 满水通道,是细菌获取营养和排除代谢废物的通道。 All biofilms have a matrix (EPS) to protect against the environment and hold colonies in place Different species, different biofilm development Mixes of polysaccharides, proteins, and nucleic acids成分The Biofilm MatrixNat Rev Micro 2010成分原理1、EPS的存在可以阻
8、止抗生素 作用- 细菌耐药性； 2、抗免疫清除：屏蔽作用使吞 噬细胞和杀伤细胞及其所分 泌的酶不能发挥作用； 3、细菌生活微环境改变：比如 厌氧菌繁殖、H2S产生、pH 改变（口臭、龋齿等） 4、Quorum sensing：参阅 , by Bonnie Basler (普林斯顿大学)细菌生物膜与抗性和特点细菌生物膜 进入体内的 可能途径临床意义 医疗器械表面、插入导管、植入医疗器具/hip replacement- 是医原性感染的主要原因之一 生物造成细菌对抗生素不敏感/耐药性 P. N. R. Nair (2006) International Endodontic Journal. On
9、 the causes of persistent apical periodontitis: a review 临床意义Apical periodontitis is a chronic inflammatory disorder of periradicular tissues caused by aetiological agents of endodontic origin. Persistent apical periodontitis occurs when root canal treatment of apical periodontitis has not adequatel
10、y eliminated intraradicular infection. Problems that lead to persistent apical periodontitis include: inadequate aseptic control, poor access cavity design, missed canals, inadequate instrumentation, debridement and leaking temporary or permanent restorations. Even when the most stringent procedures
11、 are followed, apical periodontitis may still persist as asymptomatic radiolucencies/ 射线 可透性, because of the complexity of the root canal system formed by the main and accessory canals, their ramifications and anastomoses where residual infection can persist. P. N. R. Nair (2006) International Endod
12、ontic Journal. On the causes of persistent apical periodontitis: a review与口腔的关系Further, there are extraradicular factors located within the inflamed periapical tissue that can interfere with post-treatment healing of apical periodontitis. The causes have not been well characterized, but there are si
13、x biological factors that lead to asymptomatic radiolucencies persisting after root canal treatment. (i) intraradicular infection persisting in the complex apical root canal system; (ii) extraradicular infection, generally in the form of periapical actinomycosis; (iii) extruded root canal filling or
14、 other exogenous materials that cause a foreign body reaction; (iv) accumulation of endogenous cholesterol crystals that irritate periapical tissues; (v) true cystic lesions, and (vi) scar tissue healing of the lesionHow are biofilms studied in the lab? Single-species vs. Multi-species Transparent f
15、low cells Bacteria attach to glass and nutrients flow through the cell Microscopy Bacterial culture 生物被膜的观察研究方法扫描电镜: Costerton等人在70年代通过扫描 电镜观察到了细菌的生物被膜的存在。 激光共聚焦显微镜:分子生物学方法： Huth et al 2008http:/obgyn.ufl.edu/docs/schultz_eurowound.pdfSEMcoccineutrophilbugThanksAdiosCiao谢谢Flush your teeth dailyBrush your teeth 3 times a day
